PT-2026-3858 · Arduino · Arduinocore-Avr

Published 2025-01-01 · Updated 2026-01-21 · CVE-2025-69209

Positive Technologies (AI Summary)

CVSS v4.0

6.9

Medium

Base vector

AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Name of the Vulnerable Software and Affected Versions ArduinoCore-avr versions prior to 1.8.7

Description ArduinoCore-avr, which contains the source code and configuration files of the Arduino AVR Boards platform, is affected by a stack-based buffer overflow. This occurs when converting floating-point values to strings with high precision. Passing large decimalPlaces values to the affected String constructors or concat methods causes the dtostrf function to write beyond fixed-size stack buffers, leading to memory corruption and denial of service. Under certain conditions, this could potentially allow for arbitrary code execution on AVR-based Arduino boards.

Recommendations Versions prior to 1.8.7 should be updated to version 1.8.7 or later.

Exploit

Fix

Buffer Overflow

Weakness Enumeration

CWE-120

Related Identifiers

CVE-2025-69209

GHSA-PVX3-FM7W-6HJM

Affected Products

Arduinocore-Avr

References · 15

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/69xxx/CVE-2025-69209.json · Exploit
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-69209 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2025-69209 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2025-69209 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2025-69209 · Security Note
• https://ubuntu.com/security/CVE-2025-69209 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-69209 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-69209 · Security Note
• https://github.com/arduino/ArduinoCore-avr/pull/613 · Note
• https://github.com/arduino/ArduinoCore-avr/security/advisories/GHSA-pvx3-fm7w-6hjm · Note
• https://github.com/arduino/ArduinoCore-avr/commit/82a8ad2fb33911d8927c7af22e0472b94325d1a7 · Note
• https://github.com/arduino/ArduinoCore-avr/releases/tag/1.8.7 · Note
• https://support.arduino.cc/hc/en-us/articles/24985906702748-ASEC-26-001-ArduinoCore-AVR-v1-8-7-Resolves-Stack-Based-Buffer-Overflow-Vulnerability · Note
• https://twitter.com/VulmonFeeds/status/2014082151059186122 · Twitter Post
• https://twitter.com/CVEnew/status/2014081578775814498 · Twitter Post